Benzene safety lamp for indicating fire damp



June 1 l, 19. H. FLEISSNER ,3

BENZENE SAFETY LAMP FOR INDICATING FIRE DAMP Filed Aug. 31, 192s HANS mnrssnnn, or KLEOBEN, AUSTRIA.

BENZENE SAFETY LAMP roe innicnrme FIRE- DAME.

Application filed August 31,1926, Serial no. isasia'aaa inGelfnlaliy September 12*," 12525.

This invention relates to miners safety lamps of the kind having means formeasuring the methane or flredamp content of the air in the mine'and particularly to lamps in whichthe increase in themethane content of the air is detected by a' corresponding increase in the size of the flame.

Miners lamps of the kind referred to have been proposed having a wire arranged vertically in the lamp so as to be capable of being made incandescent by the flame. It has also been proposed to superpose a plurality of loops of platinum wire directly over the wick of the lamp so as to be capable of being heated to incandescence by the flame and glowing with a red hue, the height of which varies with the .content of gas in the air of the mine. however, are only capable of measuring the height of the flame and the indications become uncertain when the lamp is held in an inclined position. Arrangements have also been proposed in which a plurality of superposed transverse wires are employed but the wires in these arrangements only act as measuring devices being arranged at a comparativelygreat distance from one another and at such a distance from the flame that they are not capable of being rendered incandescent thereby. These arrangements also can only measure the height of the flame and in this case also any inclination of the lamp will at least render the indication uncertain.

'The present invention-has for itsobject o to provide a miners safetylamp for testing the air for fire-damp, which will more clearly and reliably indicate the methane content of the air and in which the inclination of the lamp will have no influence on the indication. -ll ith this object in view, the invention consists in arranging a metallic strip vertically inside the lamp casing directly above the burner at the normal height of the flame so as to be in a position where it will be impinged upon and heated by the flame on the height thereof increasing beyond the normal height owing to the presence of methane in the air to be tested,

so as to show an incandescent patch com-- prising the image of a horizontal band of the flame having a size proportional to the methane content of the'air. r

The inventionis illustrated by way of example in theaccompa'nying drawing in V which;

Such arrangements,

' content.

Figure 1 showsan elevation partly in section of one con tructional-form of the improved safety lamp,

lic strip and Figure 3 shows a second modified form Figure 2 shows a modified form of metalmesa ofstrip arranged above the lamp burner.

In the construction shown in Figurel, the" safety-lamp comprises a casing cl provided:

with apertures fi'or admitting air to the inside of the lamp casing. Inside the easing (5 is fitted a burner c and directlyabove 7 sheet metal b, which is supported by a" stirrup use as to be capableof being impinged upon by the flame h when the latter increases in sizeowing to anyincrease in the' v methane content of the air; The shape and 1 size of the flame is shown'for different mix tures of air and methane according to ob-. servations which have been-made. will be seen that the area of the strip Z) which is impinged upon by the flame It in creases with the percentage of methane in made incandescent, the presence of methane in the air will be indicated by an incandescent patch on the strip, thersize of which increases with the size of the flame and conproportion to the methanesequently in Instead of employing a continuous, sheet metal strip 6, as shown in Figure 1, the strip may comprise a plurality of horizontal wires spaced apart at'a small distance from one Thus it theburner is arranged vertically a strip of .80 the air. As the strip Z2 is capable of being another as shown in Figure 2, which when rendered incandescent by the burner" flame will produce the,eflect of a luminous patch a number of; wires are mounted onthe stirrup ain groups crossing one another so as to form a wire gauze i of close mesh which when heated by the burner flame will show 1 a luminous patch or spot varyingin size with the size of the flame and thus with they methane content of the air to be tested.

What I claim is: 1 V 1. A miners safety lamp for testing-air V I forwthe presence of fire damp or methane, u

comprising the combination with lamp I Y casing and a burner in said casing, of a a metallic'strip mounted vertically inside the lamp casing directly above said burner, at the normal height of ,afiame .fromsaid burner, so as to be capable of being impinged upon by'th e flame and heated to incandescence by the saidflame, on the height thereof increasing beyond the normal height owing to the presence of methane in the air to be tested, said strip'when so heated being capable of showing an'incandescent patch comprising an image of a horizontal band of the flame having a length proportional to the methane content of the air.

2. A. 'miners safety lamp as set forth'in c'laiml, having the metallic strip comprising a plurality of Wires spaced apart at a 7 small distance from one another, so as to form a screen capable of showing a luminous imagetof the horizontal'band of the flame.

3. A miners safety lamp as setforth in In testimony whereofI have signed my name to this specification.

HANS; Eis'sNER; 

